Climate change has
caused the melting of ancient glaciers on tropical mountain peaks around
the world, but predictions do not go far enough about the damage to
come, a Brown University geologist recently argued in the journal
James Russell, an associate professor in Brown's Department of Earth, Environmental and Planetary Sciences,
reconstructed the temperature data of Africa's Mount Kenya over the last 25,000 years and learned that as the world rapidly warmed following the last
ice age about 18,000 years ago, the annual high temperatures on the mountain peak increased much more quickly than the temperatures at sea level.
At an elevation of 10,000 feet above sea level, the annual mean temperature rose approximately 41.9 degrees Fahrenheit, compared with a rise of approximately 35.6 degrees Fahrenheit at lower elevations.
Running state-of-the-art climate models backward, the researchers found that the models underestimated the temperature changes at high elevations. There’s also a strong implication that models might underestimate the high-elevation warming to come, Russell said.
“These are very fragile ecosystems that house extraordinary biodiversity and unique environments such as tropical glaciers,” Russell said. “Our results suggest future warming in these environments could be more extreme than we predict.”
Russell worked with former student Shannon Loomis on the research, which was supported by the National Science Foundation. Coauthors included Dirk Verschuren of Ghent University, Carrie Morrill of the University of Colorado at Boulder, Gijs De Cort of Ghent, Jaap S. Sinninghe Damsté of the University of Utrecht, Daniel Olago of the University of Nairobi, Hilde Eggermont of Ghent, F. Alayne Street-Perrott of Swansea University and Meredith A. Kelly of Dartmouth.